Power transmission



June 9, 1953 G. M. JONES EIAL POWER TRANSMISSION Filed Oct. 20, 1950 28INVENTORS GLEN HARVE N M. JONES BY Y H. DUVALL TTORNEY Patented June 9,1953 UNITED STATES PATENT OFFICE Duvall, Detroit, Mich, assignors toVickers 'I-neorporated, Detroit, Mich, a corporation of MichiganApplication October 20, 1950, Serial No. 191,114

Claims.

This invention relates to power transmissions, and is particularlyapplicable to those of the type comprising two or more fluid pressureenergy translating devices, one of which may function as a pump andanother as a fluid motor.

The invention is more particularly concerned with a vane pump or motorconstruction adapted for use in hydraulic power transmission systems.

A form or pump in common use in the hydrau lic power transmission fieldutilizes a rotor hav ing a plurality of substantially radial vanes rotatable therewith and slidable relative thereto. The rotor is mountedwithin a chamber, the contour of which forms a vane track against whichthe outer ends of the vanes are adapted to be maintained in contact. Thechamber forming the vane track may comprise the inner portion of a vanetrack ring. The vane track is adapted to control the movement of thevanes and cooperates with the rotor in forming working chambers throughwhich the vanes pass as the rotor turns. The external connection portslead by passage means to the working chambers so as to form separatefluid inlet and outlet zones.

Some means in addition to centrifugal force is utilized to maintain theouter ends of the vanes in contact with the vane track, which isessential for efficient operation. One method has been to connect thehigh pressure side of the device to the inner ends of the vanes.However, a problem arises in maintaining the contact when there is nopressure available. When the device is utilized as a motor it isparticularly important at starting operation that some slight force beemployed for urging the vanes outward in contact with the track,otherwise leakage would occur around the outer ends of the vanes andcause free wheeling of the device. It is also important that contact bemaintained as the vanes pass over the sections forming the separationbetween the inlet and outlet fluid zones. In addition, as the vanes passthrough the high pressure zone of the device, there is a tendency forthe vanes to separate from the track because of the outer ends beingexposed to said high pressure.

Attempts have been made to solve this problem by the use of individualcoil springs for each vane and which have failed to meet commercialrequirements. Ihe space available in the rotor for mounting the springsis very limited. Due to the fact that the spring is subjected to severeoperating conditions, such as the numerous flexings of each spring andthe speed at which they must contract and expand, they fatigue rapidly.In order to meet commercial operating requiremerits, the rotor sizewould have to be greatl increased to provide proper mounting area forthe larger types of springs demanded. Ihis is impractical when size,weight and cost are to be considered.

Where the individual coil spring type of construction is utilized thespring is continuously subjected to the full travel of the vane. Wherethe device is of the double throw type, i. e., each vane havingtwocomplete strokes per rotor revolution, and the rotor speed is in excessof 1000' R. P. M. it can be clearly seen that each spring is subjectedto over 2000 full travel strokes of the vane each minute. The fatiguelife of the coil spring is thus certain to be short.

In order to overcome the shortcomings of the individual coil spring typeof construction, it has been heretofore proposed to utilize resilientbell crank members for 'preloading the vanes in contact with the vanetrack and which by lever action transfer the inward motion of one vaneto outward motion of a complementary vane. In this latter type ofconstruction the bell crank member is pivotally connected at its centralportion to the rotor and the arms of the member which engage the underportions of a pair of complementary vanes resiliently preload the vanesin contact with the vane track. The motion of one vane is transferred toanother comlementar vane without substantial flex'ure of the arms.However, a problem arises in roviding bell crank members constructed sothat free pivotal movement of the adjacent arms of adjoinin'g members ispermitted. A staggered relationship of the immediately adjacent arms ofthe member is desirable and the problem of cost including labor costsduring assembly of the device must be considered.

It is therefore an object of this invention to provide an improved typeof resilient bell crank member for preloadlng the vanes in contact withthe vane track and for transferring by lever action the inward motion ofone vane to the outward motion-of a complementary vane.

It is a further object of this invention to provide bell crank membersfor the purposes stated above, the arms of which engage the inner endsof the vanes being on the same plane and which may be economicallymounted in a staggered relationship on the rotor to provide free pivotalmovement of adjacent members.

It is also an object of this invention to provide bell crank members ofan improved construction for the purposes aforementioned which areeconomical and eflicient over a long useful life.

It is another object of this invention to provide members of the typeand for the purpose mentioned which are resilient so as to produce thepreloading effect of the vanes desired but arranged to produce the leveraction required without significant bending action as the vanes travelthroughout their full strokes.

It is another object to provide a novel, economical, improved means forselectively preloading the vanes in contact with the vane track which isefficient over a long useful life.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing wherein a preferred form of the present invention is clearlyshown.

In the drawing:

Figure 1 is a sectional view of a rotary vane pump or motor.

Figure 2 is a sectional view taken on line 2-2 of Figure 1 embodying apreferred form of the present invention.

Figure 3 is an enlarged partial sectional view of the rotor illustratedin Figure 2.

Figure 4 is a partial sectional view illustrating the staggeredrelationship of the bell crank members on opposite sides of the rotor.

Referring to Figure 1, there is shown a rotary vane type of pump ormotor indicated generally by the numeral ID, the body of which comprisesa right end housing member l2 and left end housing member I4 sandwichedbetween and suitably bolted to which is a central housing member or camring IS. The right end housing member I2 is provided with an externalconnection port I8 and the left end housing member with an externalconnection port 20.

The inner-contour of the cam ring I6 indicated by the numeral 22 issubstantially elliptical in shape. Mounted within the cam ring i6 is arotor 24 provided with a plurality of substantially radial slots 26within which vanes 28 of rectangular shape are slidably mounted. Theouter ends of the vanes are adapted to be urged in contact with thecontour of the cam ring, which will hereinafter be referred to as thevane track, by pressure fluid directed to the inner enlarged ends of theslots and indicated by the numeral 30.

Pressure fluid is adapted to be conducted to the enlarged portions 30from a pressure chamber 32 connected to the external port 20. Thepressure chamber 32 is connected to the enlarged portions of the vaneslots by means of a plurality of ports 34 in a side plate 36 mounted inthe pressure chamber 32. The side plate 36 is initially urged against aportion of the cam ring l6 and in fluid sealing engagement with therotor 24 by a spring 38. During operation of the device pressure fluidin the pressure chamber which is equivalent to the pressure in port 20will maintain the side plate in fluid sealing engagement with the rotor24.

The rotor is provided with a shaft 40 spline connected thereto at 42 andwhich is rotatably mounted on bearings 44 and 46 within the right endhousing member [2. The port I8 is connected by branch passages 48 and 50which open to diametrically opposed working chambers 52 and 54 of thedevice. A pair of diametrically opposed fluid openings in the sideplate, not shown, are adapted to connect other remaining portions of theworking chamber to the pressure chamber 32 which is connected to theport vanes.

The contour of the cam ring cooperates with rotor and vanes to producetwo complete inward and outward strokes of each vane during a rotorrevolution. For each vane on an inward stroke there is a complementaryvane which is on a corresponding outward stroke. The complementary vanesin the double throw unit shown are degrees apart but it should beunderstood that in a single throw unit the spacing will be degrees, in atriple throw unit 60 degrees, etc. For the purpose of preloading thevanes in contact with the vane track 22, such as for maintaining theouter edges in contact therewith at starting and when there is nopressure, there is provided a plurality of bell crank members 56. Eachmember is provided with two arms 58 and 60 which are in the same planeand the member is partially coiled or looped at its central portionindicated by the numeral 62. The bell crank members 56 are mounted incircular recesses 64 formed in opposite faces of the rotor 24 and onextending portions 61 of pins 68 rotatably mounted in bores 10 openingat opposite ends to the recesses. Each pin 68 is provided with a groove12 near each end portion thereof and the central portion 62 of themember 56 may be snapped into the groove so as to be pivotally connectedto the rotor. The bell crank members lie between the planes containingthe axially spaced edges of the The arms of each member underlie theinner ends of all intermediate vanes within the span betweencomplementary vanes and are bent to avoid interference with intermediatevanes and at their ends to engage the inner ends of complementary vanesin a manner to resiliently load said vanes in engagement with the track.

Due to the fact that the arms of the members 56 are on the same plane,free pivotal movement of the members so as to produce a lever action bythe arms thereof, is provided by staggering these members on oppositesides of the rotor. Washers T2 are provided for alternate members oneach side of the rotor. They are placed on the ends of the pins betweenthe rotor and the bell crank member, and the looped portion of themember retains the washer on the pin. In this manner, each member isstaggered in position with respect to the adjoining members on each sideof the rotor.

In operation as one vane begins an inward stroke, its complementary vanewill begin an outward stroke. As the vane track causes the inward strokeof each vane the inward motion thereof will be transferred by leveraction by one arm of the member to produce an outward or upward motionof the other arm and its complementary vane. The arms of the members,being resilient, preload the vanes in contact with the vane track 22.This is an important advantage at starting when operating the device asa motor. In addition when operating the device as a motor it isadvantageous to provide an additional force to maintain the vanes incontact with the rings when they pass through the inlet fluid zones ofthe working chambers. At this time there is a tendency for the vanes toseparate from the vane track which would cause leakage and freewheeling. The arms are of sufficient strength to produce by lever actionthe outward motion of one vane by transferring thereto the inward motionof its complementary vane without substantial flexure of the arms of themember.

The construction therefore avoids the disadvantages of priorconstructions wherein individual coil springs were provided for eachvane which were repeatedly subject "to compression leading to shortfatigue life. The arrangement whereby a washer is placed behindalternate members at the central portion thereof provides an economicalmeans of providing a, staggered relationship of alternate members onopposite sides of the rotor. This simplifies the construction of thebell crank members and its associ ated mounting parts and provides freepivotal movement of the adjoining members.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within thescope of the claims which follow.

What is claimed is as follows:

1. In a fluid pressure energy translating device of the rotary vane typecomprising a "housing having a vane track and a rotor mounted within thetrack having a plurality of generally radial slots, each slot having avane slidably mounted therein the outer end of which is adapted to beconstantly urged against the track, said track causing complete inwardstrokes of the vanes during a rotor revolution and each vane on aninward stroke having a complementary vane adapted to be on an outwardstroke, that improvement comprising a plurality of bell crank memberseach of which is pivotally mounted at its central portion on the rotorbetween a pair of complementary vanes, the arms of each memberunderlying the inner ends of all intermediate vanes within the spanbetween complementary vanes and the outer ends of the arms engaging theinner ends of complementary vanes, said arms of each member beingflexible to resiliently load the vanes in engagement with the track andbeing of suiiicient strength to transfer by lever action withoutsubstantial flexure the inward motion of one vane to its complementaryvane to cause the outward stroke of said vane, the arms of each memberbeing on the same plane, and means staggering the members in two planeson the rotor to avoid interference between the arms of adjacent members.

2. In a fluid pressure energy translating device of the rotary vane typecomprising a housing having a vane track and a rotor mounted within thetrack having a plurality of generally rad1al slots, each slot having avane slidably mounted therein the outer end of which is adapted to beconstantly urged against the track, said track causing complete inwardstrokes of the vanes during a rotor revolution and each vane on aninward stroke having a complementary vane adapted to be on an outwardstroke, that 1mprovement comprising a plurality of opposing pairs ofbell crank members on the rotor, each of which is pivotally mounted atits central portion on the rotor between a pair of complementary vanes,the arms of each member being bent to avoid interference with allintermediate vanes within the span between complementary vanes and attheir outer ends to engage the inner ends of complementary vanes, saidarms of each member being flexible to resiliently load the vanes inengagement with the track and being of sufficient strength to transferby lever action without substantial flexure the inward motion of onevane to its complementary vane to cause the outward stroke of said vane,the arms of each member being on the same plane, and means forstaggering alternat members in two planes on opposite sides of the rotorto avoid interference be tween the arms of adjacent members.

3. In a fluid pressure energy translating device of the rotary vane typecomprising a housing having a vane track and a rotor mounted within thetrack having a plurality of generally radial slots, each slot having avane slidably mounted therein the outer end of which is adapted to beconstantly urged against the track, said track causing complete inwardstrokes of the vanes during a "rotor revolution and each vane on aninward stroke having a complementary vane adapted to be on an outwardstroke, that improvement comprising a plurality of bell crank memberseach ogfwhich comprises a single strand of wire having a loop at itscentral portion and the'arms of which are in the same plane, a pluralityof pivot pins mounted'in the rotor the ends of which extend fromthearo'tor. one between each pair of complementary vanes, and a bellcrank member pivotally mounted on each end of each pin, the membersbeing mounted by their loop portion on the ends of said pins, the armsof each member being bent to avoid interference with all intermediatevanes within the span between complementary vanes and at their ends toengage the inner ends of a pair of complementary vanes, said arms of themembers being flexible to resiliently load the vanes in contact with thetrack and of sufilcient strength to transfer the inward motion of onevane to its complementary vane to cause the outward stroke of said vane,and means for staggering the members in two planes on the pins to avoidinterference between the arms of adjacent members.

4. In a fluid pressure energy translating device of the rotary vane typecomprising a housing having a vane track and a rotor mounted within thetrack having a plurality of generally radial slots, each slot havin avane slidably mounted therein the outer end of which is adapted to beconstantly urged against the track, said track causing complete inwardstrokes of the vanes during a rotor revolution and each vane on aninward stroke having a complementary vane adapted to be on an outwardstroke, that improvement comprising means forming recesses on oppositefaces of the rotor, a plurality of pivot pins mounted in the rotor theopposite ends of which extend into the recesses, one between each pairof complementary vanes, a plurality of bell crank members each of whichcomprises a single strand of wire having a loop at its central portionand its arms on the same plane, said bell crank members being pivotallymounted by their loops on the pins, there being one bell crank member oneach end of each pin, the arms of each member being bent to underlie theinner ends of all intermediate vanes within the span betweencomplementary vanes and at their outer ends to engage a pair ofcomplementary vanes, said arms being flexible to resiliently load thevanes in engagement with the track and of suificient strength totransfer by lever action without substantial flexure the inward motionof one vane to its complementary vane to cause the outward stroke ofsaid vane, and means for staggering alternate members in two planes onthe pins on opposite sides of the rotor to avoid interference betweenthe arms of adjacent members.

5. In a fluid pressure energy translating device of the rotary vane typecomprising a housing having a vane track and a rotor mounted within thetrack having a plurality of generally radial slots, each slot having avane slidably mounted therein the outer end of which is adapted to beconstantly urged against the track, said track causing complete inwardstrokes of the vanes during a rotor revolution and each vane on aninward stroke having a complementary vane adapted to be on an outwardstroke, that improvement comprising a plurality of bell crank memberseach of which is pivotally mounted at its central portion on the rotorbetween a pair of complementary vanes, said bell crank members lyingbetween the planes containing the axially spaced edges of the vanes andthe arms being bent to avoid interference with all intermediate vaneswithin the span between complementary vanes and at their outer ends toengage the inner ends of complementary vanes, said arms being onthe sameplane and being flexible to resiliently load the vanes in engagementwith the track, and said arms being of sufli'cient strength to transferby lever action without substantialflexure the inward motion of one vaneto its com-' plementary vane to cause the outward stroke thereof, andmeans for staggering the members 5 in two planes on the rotor to avoidinterference between the arms of adjacent members.

GLENN M. JONES. HARVEY H. DUVALL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,284,083 Flinn Nov. 5, 1918 15 1,303,745 Vogan May 13, 1919FOREIGN PATENTS Number Country Date 499,923 France 1919

